python 40 line drop-in replacement for sendmail/postfix etc - avoid setting files when only using mail to send system notifications to fixed address

sendmail-mailgun.py

#!/usr/bin/env python3

import os
import sys
import subprocess

s = ""
s += "---- begin args ----\n"
for i in range(0,len( sys.argv )):
    s+= "argv[" + str(i) + "]:" + str(sys.argv[i]) +"\n"
s += "---- end args----\n"

s += "---- begin message body ----\n"
for line in sys.stdin:
    s+=line
s += "---- end message body ----\n"

cmdlist = [
    '/usr/bin/curl',
    '-s',
#    '--trace-ascii', '/tmp/mg1.log',
    '--user', 'api:key-xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx',
    'https://api.mailgun.net/v3/example.com/messages',
    '-F', 'to=user@gmail.com',
    '-F', 'from=sendmail@example.com',
    '-F', 'subject=sendmail',
    '-F', 'text=<-'
]

p=subprocess.run(cmdlist, input=s.encode(),
                 stdout=subprocess.PIPE,
                 stderr=subprocess.PIPE)

print("return code: {}\nstdout:\n{}\nstderr:\n{}\n".format(
    p.returncode, p.stdout, p.stderr))